如何使用结构键解开带连字符的json字符串？

Question

I have following code which is ok, it will print Bob:

package main

import (
    "encoding/json"
    "fmt"
)

type User struct {
    UserName string  // line2
    Age  int
}

func main() {
    var u User
    str := `{"userName":"Bob", "age": 20}` // line1
    json.Unmarshal([]byte(str), &u)
    fmt.Println(u.UserName)
}

Unfortunately, in real case, the json string in line1 is next, which you could see there is a hyphen(-) in the key.

str := `{"user-Name":"Bob", "age": 20}`

And as you all know, to automatically unmarshal the json string, we have to define a member in struct which is the same name of the key in json string, of course need to make it upper case. So I tried to change line2 to User-Name string, but - is not valid in go variable name. What should I do?

Answer 1

Simply use struct tags to map struct fields to JSON properties:

type User struct {
    UserName string `json:"user-Name"`
    Age      int
}

With this it will work, try it on the Go Playground.